Field of the Invention
The present invention relates to a method for manufacturing a semiconductor substrate in which an impurity diffusion ingredient is diffused into a semiconductor substrate by a thin film formed using a diffusion agent composition comprising an impurity diffusion ingredient and a Si compound that is hydrolyzable to produce a silanol group.
Related Art
Semiconductor substrates used in semiconductor elements such as transistors diodes and solar batteries are manufactured by diffusing impurity diffusion ingredients such as phosphorus and boron into the semiconductor substrates. For such semiconductor substrates, in the manufacture of semiconductor substrates for multigate elements such as Fin-FET and nanowire FET, in some cases, for example, impurities are diffused into semiconductor substrates having on their surface a three-dimensional structure having nanometer-scale microvoids.
For example, ion implantation (see, for example, Patent Document 1) and CVD (see, for example, Patent Document 2) are known as methods for the diffusion of an impurity diffusion ingredient into the semiconductor substrate. In the ion implantation method, an ionized impurity diffusion ingredient is implanted into a surface of a semiconductor substrate. In the CVD method, an impurity diffusion ingredient is diffused from an oxide film into a semiconductor substrate by forming an oxide film of silicon oxide or the like doped with impurity diffusion ingredients such as phosphorus and boron by CVD and then heating the semiconductor substrate with the oxide film formed thereon in an electric furnace or the like.    Patent Document 1: Japanese Unexamined Patent Application, Publication No. H06-318559    Patent Document 2: PCT International Publication No. WO2014/064873